Now this is something new: since when is Java requiring that serializable objects provide their own UIDs? That was never the case unless you wanted to guarantee that an inner class be serializable. I suspect that we're seeing a rule violation in Eclipse's internal compiler. Sean On May 31, 2006, at 11:14 AM, Harri Salakoski wrote: > I answer easy ones. >> I am also getting the following error within eclipse in the >> Add.Java file: >> public class Add extends GPNode....The serializable class Add does >> not >> declare a static final serialVersionUID field of type long > Add following line for "Add" class. > > private static final long serialVersionUID = 1L; > >> Could someone please help me to understand why this is occurring. > http://www.javapractices.com/Topic45.cjp > > Eclipse has possibility define more varnings on or off, often > warning level things are not severe mostly just anonying in big > projects. > If you use several different JDK:s example both linux and windows > enviroments to previous warning is more important than using only > on JDK in enviroment that calculates default seralVersionUID right. > > t. Harri > >> Sincerely, >> >> Gerard >> >> I have not included the libraries list since I believe this is >> unnecessary.